The metabolism of purine in liver is being investigated, particularly in regard to the effects of ethanol administration. In man, alcohol ingestion or infusion causes elevated uric acid production and hyperuricemia. These changes are accompanied by elevated acetate and phosphate concentrations in the blood, and elevated acetate, phosphate and pyrophosphate contents in rat liver. We are investigating in rats, the effect of ethanol administration, given in the absence or presence of an inhibitor of alcohol dehydrogenase; the effects of the metabolic product acetate; and the effects of phosphate, the plasma concentration, of which is known to fluctuate with ethanol ingestion. These compounds are administered to rats and the livers quick-frozen after 30 minutes. We have completed a study which focussed on the salvage of purines: the enzymes of the metabolic pathway, the carbohydrate compounds, coenzymes, purine bases and nucleosides. The methods for measurement of enzyme activities, and the purine compounds have been newly developed and validated. Further studies are being pursued concerning the changes in free [Mg2+] in lever observed after ethanol treatment of rats as indicated by the citrate/isocitrate ratios.